JPS62292176A - Golf club shaft and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 3. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improved golf club shafts and methods of manufacturing golf club shafts.

The shaft is the most important part of the golf club. The shaft connects the golfer to the club head that hits the ball, and the shaft is the main component that allows the golfer to control the club head when making shots to the head. The ease of hitting a golf club and its "feel" (in other words, the performance of a golf club that reproduces the golfer's intended shot and builds confidence in the golfer through the golfer's kinesthetic sense that allows the golfer to make the intended shot. >> mainly depends on the shaft of the golf club.

During a golfer's backswing, the golf club is accelerated and moved rather slowly to the top of the golfer's backswing, and the golf club shaft is thick (although the golf club shaft is thick, so the feel of the club head is conveyed through the golfer's grip at the end of the shaft). We must convey this to golfers. However, when a golfer makes a shot from the top of the backswing, the golf club first experiences bending and twisting forces on the golf shaft due to the high acceleration and off-center weight of the club head, and then the club head moves away from the stationary ball. When hitting the ball, often hitting the ground on which it rests, it is also subject to sudden bending and twisting forces.

The combined forces exerted on a golf club are further complicated by the variety of terrain on which golf is played. The topography of some golf courses is soft, lush grass growing on soft soil with sufficient water. However, on other golf courses, the grass is thin and sparse, growing on hard clay. Still other courses are built on sandy or loamy soil. Each of these different conditions exerts different forces on the golf club shaft when the golfer hits the pole from the surface of the course. Additionally, golf club shafts often must be used to drive poles through the sand of dense, deep vegetation or bunkers that grow away from the fairways of golf courses. Under all of these conditions, it is desirable that the golfer be confident in performing the intended shot with the golf club.

As a result of the forces applied to the golf club during a shot, the golf club shaft bends and twists somewhat along its longitudinal axis as the golfer swings the club from the top of the backswing toward the ball. Because of the elasticity of golf club shafts, bending and twisting of the shaft is released by rapid acceleration at the top of the backswing, and this release period (timing of bend recovery) depends on the golfer's consistency in hitting the ball and on the club. is an important factor in playability and feel. The golf club shaft also stores energy during the bend of the shaft when the golfer accelerates the club from the top of a banked swing; when the clap head strikes the ball, the golf club shaft stores energy as the golfer returns the golf club shaft to its original straight position. If you can time the elasticity of the golf club shaft, you can return that energy to the ball when you hit the ball. The return of energy by the golf club shaft to the club head and the golfer's ability to time his swing to take advantage of that return of energy are two factors that allow him to hit the distance with a golf ball when desired. The ability to hit a golf ball a long distance is always an advantage in the game of golf. Of course, this means that for best results, the golf club shaft must match the release of stored energy through flex with the natural tempo of the golfer's golf swing when using the club. It means not to be.

Torsional deflection of the shaft and the release of stored energy as a result of such torsional deflection, although this release theoretically imparts a small amount of energy to the golf ball and may contribute to the distance of the shot, is generally desirable. do not have. This is because any angular deviation of the club face from the intended flight line will result in an angular error in the intended flight of the golf ball, which is almost always undesirable.

18 It is important and desirable to minimize the weight of a golf club shaft to the extent possible and consistent with providing the desired bending characteristics of the golf club shaft. Also,
It is also important that the golf club as a whole is not too heavy and feels easy to control in the golfer's hands. For maximum energy transfer from the golf club to the ball, it is desirable to concentrate the maximum amount of the golf club's weight immediately behind the ball, or at the face of the golf club, when the golf club strikes the ball. Thus, the main portion of the weight of the golf club is concentrated behind the surface of the ball, releasing the energy stored in the shaft of the golf club as the ball leaves the face of the golf club, and releasing the energy stored in the shaft of the golf club, and Minimizing the angular deflection of the golf club from its original position is a desirable characteristic of a golf club resulting from the use of a highly desirable golf club shaft.

The golfer population, of course, is nearly limitless in diversity in age, strength, flexibility, athletic ability, body size, hand/eye coordination, kinesthetic ability, ability to concentrate, and ability to perform golf shots. Thus, golfers rely heavily on physical strength; golfers rely heavily on flexibility and physique; still other golfers have a natural combination of strength, flexibility, physique, and the ability to make golf shots, and of course many Golfers lack the ability to play golf. Due to the infinite variety of physical differences and abilities of golfers, there is an infinite variety of golf club shafts that can be used to improve a golfer's ability to swing the club and reproducibly achieve the intended golf shot. It can give the golfer the best possible connection with the golf club's ability to perform.

Of course, it is impossible for a golf club manufacturer to stock the almost infinite variety of golf club shafts required to meet this requirement, even for a single club in a club set. This problem for golf club manufacturers is further compounded by further changes in the length of golf shafts required to manufacture the large number of clubs used to play golf. The length of the golf club shaft is, for example, approximately 42 inches (106,68c+++) to 43 inches (109,
22cm) to approximately 31 inches (78,74cm) to 32 inches (8,13cm) of pitching iron shafts.
), and a normal full set of golf clubs contains approximately 12 to 14 clubs;
~Each of the 14 clubs has a different length shaft. Further, the length of the shaft ideally changes depending on the golfer's height, and the matching between the golf shaft and the golfer's height is generally determined by the height from the ground surface on which the golfer stands to the golfer's hands.

Golf club manufacturers are developing the exact specifications of golf club shafts necessary to meet the various length and bending characteristics needed to produce clubs with the right shotability and feel for the various golfers who play the game. There is no room to stock up on inventory. In order to minimize inventory of golf club shafts and reduce the golf manufacturer's investment in such inventory, golf club manufacturers often offer five standard flexes for golf club shafts.
Flex) is used. These five types of standard deflection are generally extra stiff,
Referred to as Stiff, Regular, Flex and Women's, these standard deflections are used for both carbon steel shafts, the type used in a large number of clubs, and clubs made from fiber/resin composites. Ru.

In the manufacture of steel shafts, attempts have been made to adjust the deflection and feel of the shaft by forming straight sections of different diameters on the steel shaft, thus making it possible to adjust the diameter of the steel shaft to various lengths of the shaft. By adjusting this part, the deflection of the shaft can be adjusted. Structurally, shaft deflection increases as the moment of inertia of the shaft's cross-section (generally diameter) decreases. The bending properties of steel shafts can be varied only slightly by changing the composition of the steel from which the shaft is made. Manufacturing golf club shafts from resin/fiber composites increases the opportunity to vary the bending properties of the shaft and generally provides a lighter weight shaft.

There have been many attempts in the past to solve the inventory problem and provide golf club shafts that are suitable for a variety of golfers. Examples of patents directed to such prior art efforts include U.S. Patent No. 1,594,801;
．． No. 345; No. 3.313.541; No. 3,963;
No. 236; No. 4,122,593; No. 4,240.6
31 and 4,455,022, as well as British Patent No.
, No. 246,539. Of the above patents, US Pat. Nos. 2,934,345; 3,313,541 and 4,455,022 are directed to golf club shafts having glass fibers. U.S. Patent No. 4,
No. 122,593; No. 4,240,631; No. 4,4
No. 55.022 and British Patent Specification No. 1,246,5
No. 39 is directed to a single master club shaft that is cut to provide variable length and bending characteristics to accommodate different golf clubs and different golfers in the field.

However, these prior art attempts have allowed a variety of lengths and kinematics to provide golf club sets that feel good to golfers of all abilities, and have reduced shaft inventories for golf club manufacturers while providing a comfortable golf club set for golfers of all abilities. The problem of providing a golf club shaft that can produce a golf club that matches the height, physical strength, swing tempo, physique, and kinematics of a golfer has not been satisfactorily solved.

Kuri Ili! The present invention has a wall comprising a plurality of fiber layers and a resin bonding the plurality of fiber layers together in a unitary structure, and has a constant wall portion adjacent one end adapted to receive a grip. A generally hollow tapered golf club shaft having a diameter section and a smaller constant diameter section adjacent the other end adapted to fit into the hosel of the club head. This shaft has a length of approximately 45 to 4 inches (114,3 to 119.38 cm) for woods such as drivers, and approximately 39 to 41 inches (99,06 to 104,1 cm) for irons.
4cm). A portion of the shaft intermediate the constant diameter ends is formed with a uniformly tapered diameter. This shaft allows golf club manufacturers to provide golf clubs with adjustable deflection by shortening the shaft at the larger diameter end, the smaller diameter end, or both ends. .

The golf club shaft resists torsional deflection and provides a predetermined variable deflection that allows the player to utilize the energy stored in the shaft during the swing and apply that energy to the ball to increase distance. The shaft includes a plurality of fiber layers configured and selectively oriented within the shaft. The fibers of the shaft are bonded together by an adhesive resin, preferably an epoxy, to form an integral whole. The inner fiber layer and the outer fiber layer have fibers that extend perpendicular to the longitudinal axis of the shaft and fibers that extend longitudinally along the axis of the shaft to accommodate deflection of the shaft. The inner layer allows for varying deflections along the longitudinal axis of the shaft and varying resistance to torsional deflection of the shaft.
The fibers extend lengthwise along the axis of the shaft or are oriented helically at a selected angle about the axis of the shaft. In longer shafts, such as wood shafts, two of the fibers are oriented at an angle.
A layer is added to the shaft, preferably on its inner layer only adjacent its small diameter club head end.

To manufacture the shaft, the resin-impregnated fiber cloth is cut into inner and outer blanks having fibers that are slightly longer than the shaft and extend parallel and perpendicular to the length. One or more central blanks slightly longer than the shaft are cut from the closely parallel rows of fibers, with the fibers extending parallel to the length of blank or at a selected angle. Prepare a steel mandrel at a somewhat higher temperature. Wrapping the fiber material around a steel mandrel with inner and outer groups of layers having fibers extending perpendicularly and parallel to the longitudinal axis of the mandrel and along or along the longitudinal axis of the shaft. A shaft is formed with a central group of layers having fibers extending circumferentially at selected angles. When manufacturing shafts for irons, additional torsional resistance must be considered.

This is because when a good player makes a golf shot with an iron, he inevitably makes a deliberate strike between the clubhead of the iron and the ground, that is, a good player takes a divot with the iron shot. be. Such blows apply severe torsional forces to the golf club shaft. The effects of such torsional forces are reduced by the inclusion of angularly oriented fibers, preferably in the central layer of the shaft. When producing longer shafts with more deflection, additional fiber layers are typically added.
Wrap the mandrel intermediate the inner group layer and the center group layer and adjacent the smaller diameter end of the shaft to which the club head will be attached. When manufacturing these flexible shafts, this additional fiber layer is added to a material having a length of approximately 40% of the length of the shaft and having fibers oriented at a complementary angle of preferably 45 degrees to the length. the material is cut from a resin-impregnated fiber cloth as a material; this material is placed over the inner material such that the fibers are oriented at 45 degrees to the solid axis of the shaft and extend from the tip of the shaft for approximately 40% of the length of the shaft. Wrap it around.

When the material is wrapped around the mandrel, the mandrel and material are pressed together, preferably with tightly wrapped plastic tape; the shaft and mandrel are placed in a hot open for a sufficient period of time to cure the resin and bond the fibers and resin together. to obtain a shaft that is easy to hit and has excellent feel.

FIG. 1 is a partially sectional plan view of a golf shaft 10 of the present invention. This golf shaft 10 is hollow and has three parts. One end portion 11 has a constant outer diameter, preferably about 0.620 inches (1,57 inches Q cn), and extends several inches from one end of the shaft.

The second portion of constant diameter has a smaller diameter, preferably
Outer diameter of approximately 0.335 inches (0,851 cm) to approximately 0.
375 inches (0,953 cm), inner diameter approximately 0.230
inch (0,584 cm) and extends several inches from the other end of the shaft. The central portion 13 of the shaft extends between the end portions 11 and 12 with a uniformly decreasing taper from the thicker portion 11 to the narrower portion 12. The length of the shaft end portion 11.12 is such that a constant diameter section can be trimmed from the golf shaft in adjusting the golf shaft to the shaft length required for a particular club and the bending characteristics desired by the golfer. several inches long. By several inches, section 11 has a length of about 8 inches (20.32 cm) to about 12 inches (30.48 cm);
2 is about 4 inches (10,16 cm) to about 8 inches (2
0.32 cm). In a preferred embodiment of shaft 10 for wood, section 11 is approximately 12 inches (30,48 CII) long;
2 is approximately 6 inches (15,24 cm+) long.

In a preferred embodiment of shaft 10 for an iron, portion 1
1 is about 8 inches (20,32 cm) long, and part 1
2 is approximately 4 inches (10,16 (Jl) long).

The golf club shaft IO is comprised of multiple fiber layers and a resin that adheres the fibers into a unitary structure. The golf shaft IO has a tapered structure that is hollow throughout and has a wall portion 10a of uniform thickness.

A cross section of the wall portion 10a of the wood golf shaft 10 is shown in FIG. 1A. The wall 10a of the golf shaft IO preferably comprises 6 to 8 layers of glass fibers. Each layer of glass fiber is applied to the wall of the shaft by approximately 0.
The total wall thickness of the preferred fiberglass shaft is approximately 0.048 inches (0.123 cm). As shown in Figure 1,
The golf shaft consists of three separate groups of layers 15-17.

The inner group 15 consists of two to three glass fiber layers, including a number of glass fibers 15a extending generally parallel to the solid axis 10b of the shaft 10 and substantially perpendicular to the solid axis 10b of the shaft. A large number of glass fibers 15 extending around the solid axis 10b of the shaft 10
It is woven to have a b. The central group 16 has approximately two layers and consists of a number of glass fibers extending substantially parallel to the axis 10b of the shaft 10. The outer group 17 consists of 2-3 layers for flexible shafts and 3-4 layers for more rigid shafts. The glass fibers of the outer layer include fibers 17a extending generally parallel to the longitudinal axis 10b of the shaft 10 and fibers 17a extending around the longitudinal solid axis 10b of the shaft 10 and located approximately perpendicular thereto. 17b.

The thicker end 11 of the shaft 10 is adapted to receive a grip, as is known in the art, which grip often fits the player's hand and provides a comfortable grip for the player. It is a molded rubber member that is fitted into the end portion 11. The other narrow end 12 has a uniform diameter extending 8 inches (20.32 cm) from the end and is adapted to fit into the hosel of a wood golf club head.

FIG. 2 is a diagram of a steel mandrel 20 for manufacturing golf club shaft 10. As shown in FIG.
372cn) outside diameter and about 18 inches (45,72cn)
It has a first portion 21 in the form of a perfect circular cylinder having a length of m+). The first portion 21 of the steel mandrel forms the first portion 11 of the golf club shaft adapted to receive the grip. steel mandrel 20
has an outside diameter of 0,230 inches (0,584 cm) and extends from the other end of the mandrel.
A second cylinder in the form of a perfect circular cylinder having a length of cI11)
It has a portion 22. The second portion of the steel mandrel 20 forms the tip of a golf club shaft that is adapted to fit into the hosel of a golf club head.

The third intermediate portion 23 of the steel mandrel extends 28 inches (71,12 cm) between the first and second portions 21 and 22 of the steel mandrel and has a diameter of 0.54 cm at the gripping end.
0.23 at the tip from the large diameter of inch (1,372 cm)
It tapers uniformly to a diameter of inches (0,584 cIm). Thus, the total length of the steel mandrel is approximately 54
inch (137,16 cm).

FIG. 3 shows the inner layer 1 of the golf club shaft 10 for wood.
FIG. 5 is a plan view of a base material or inner material 30 of resin-impregnated glass fiber cloth cut to form a fiberglass material 5; As shown in FIG. 3, the blank 30 is polygonal with a straight base 33, a wide end 31, and a narrow end 32 about 4 inches (119.38 cm) long. The ends 31,32 are generally located at right angles to the base 33. The wide end 31 has a width of approximately 5.20 inches (13.21 cm) and the narrow end 32 has a width of approximately 2.4 inches (6.10 cm) for a more flexible golf shaft, and a stiffer shaft. A golf shaft has a width of approximately 4.1 inches (10,414 cm). As seen in FIG. 3, the fourth side 34 of the polygon is parallel to the base side 33 for a distance extending approximately 12 inches (30,48 cm) from the end 31.
a and a second portion 34b parallel to the base 33 for a distance extending approximately 6 inches (15,24 cm) from the end 32.
has. Portions 34a and 34b of the sides 34 are the central portion 34
C, and this central portion 34c uniformly reduces the width of the material 30 between the larger end 31 and the smaller end 32 of the material 30. As can be seen in FIG. 3, the material 30 is
It is cut from a resin-impregnated glass fiber cloth with glass fibers extending at right angles to each other. Certain preferred fiberglass cloths are manufactured by, for example, Clark Schunipel Co.
4557 type of S-2 glass, such as that manufactured by 1ark-3chwebel Corp., in which the majority of the glass fibers (57 per inch (2,54 cm) of warp threads) are The glass fiber cloth is cut so as to extend parallel to the base side 33 of the material as indicated at 158 in FIG. A small portion of the fabric's glass fibers 15b (30 per inch weft) extend approximately perpendicular to the base 33 of the material and the fibers 15a. Although the ratio of the number of glass fibers extending parallel to the base 33 and the number of glass fibers extending in the lateral direction of the base 33 is not intended to be limited, it is noted that the ratio of the number of glass fibers extending parallel to the base 33 as indicated by 15a is Preferably, there are approximately twice as many glass fibers extending perpendicularly to the base 33 as shown at 15b.

FIG. 4 shows a tip insert 40 of the type that would be incorporated into a wood golf club shaft having greater deflection. The tip insert material 40 is approximately 20 inches (5.5 cm) long.
0,8cI11) base 43, 4 for this base 43
It is trapezoidal in shape with an end 41 forming an angle of inclination of 5 degrees and a second end 42 extending perpendicularly from the base 43. A fourth side 44 of the insert blank extends parallel to the base 43 between the first side 41 and the second side 42 . The width between the base 43 and the fourth side 44 of the tip insert 40 is preferably about 1.5 mm, as described below. 2.5 inches (4,318 cm) to approximately 2.5 inches (6,35 cm). The tip insert blank 40 is cut from the same glass fabric as the base blank 30 (FIG. 3), but the tip insert blank 40 has the glass fibers oriented at 45 degrees to the base 43 as shown in FIG. It is cut so that it is oriented at the supplementary angle of .

Thus, the tip insert 40 is arranged such that the majority of the fibers 18a form an included angle of 45 degrees with the base 43 and the vertical fibers of the glass cloth 18b form a complementary angle of 45 degrees with the base 43. be cut.

The tip insert 40 does not substantially increase the longitudinal stiffness of the shaft when incorporated into the shaft because the glass fibers are oriented at an angle to the axis of the shaft;
Due to increasing its torsional stiffness, reducing its torsional deflection, and separating the glass fiber at its narrow end,
Substantially reduces the tendency of the shaft to fail.

FIG. 5 shows a glass blank 50 used to form the central layer of glass fibers 16 of the golf club shaft 10. As shown in FIG. As shown in FIG. 5, blank 50 for central layer 16 has a straight base 53 having a length of approximately four inches (119,38 cm), a first end 51 and a second end 52. The fourth side 54 extends between the ends 51,52 and uniformly reduces the width between the fourth side 54 and the base 53. The first end 51 is preferably about 3.9 inches (9.91 cm) wide, and the narrow end is preferably about 1.9 inches (9.91 cm) wide.
The width is 4.83 cab). The central stock 50 is cut from parallel rows of resin-impregnated glass fibers extending in only one direction. The material for the central material 50 is, for example, manufactured by Ferro Co., Ltd. (F
A unidirectional glass tape of S-2 glass fiber, such as that manufactured by Erro Corp. This material 50 is cut so that the glass fiber 16a making up this material is substantially parallel to the base 53. The blank 50 is used to manufacture shafts of all flexures.

FIG. 6 shows blank 60 for the outer layer of glass fiber 17 that makes up golf shaft 10. FIG. This material 6
0 has a straight base 63 about 4 inches long (119.38c+a), a first end 61 and a second end 62. The ends 61 , 62 lie substantially at right angles to the base 63 . The fourth side 64 is about 12 inches (3 inches) from the end 61.
The first portion 64a extends parallel to the base 63 for approximately 6 inches (15,24
cm) and extends parallel to the base.

The middle portion 64c of the side 64 has portions 64a at both ends thereof.

64b are interconnected. In the manufacture of more flexible golf shafts, the first end 61 is approximately 5.5 mm wide. Finch (14,4
8c+a), and the second end 62 is approximately 2.9 inches wide (7
, 37cm). For harder golf clubs, the first
The end 61 is approximately 7.5 inches (19,05 cn) wide;
Second end 62 is approximately 4 inches (10,160) wide. Outer blank 60 is cut from the same glass fabric as inner blank 30 and tip insert blank 40.

Similar to the inner material 30, the outer material 60 is constructed such that the majority of the glass fibers of the glass fabric are oriented parallel to the base 63 as indicated at 178, with the lateral fibers 17b located substantially perpendicular to the base 63. It will be cut as follows.

In order to provide three different types of golf shafts with inherently different longitudinal axis bending characteristics, the present invention provides three different types of golf shafts with the same inner diameter but with variable wall thickness in critical areas of the shaft. The shaft 10 is manufactured by selecting a combination of materials to obtain the following.

These three different grades of shafts, designated as 1-2.3-4.5-6, have uniformly spaced deflections throughout the most desirable deflection range, and can be graded 1-6 by simple cutting. It exhibits six standard deflections and variable deflections between these six standard deflections.

The table below shows a selection of materials used in combination with a common central stock 50 to produce the three types of wood shafts of the present invention.

Inner material Outer material Tip insertion (30)
(60) Human body (4o) 1-2
5.2 2.4 5.7 2.9 2.5 (1
3,21) (6,10) (14,48) (7
,37) (6,35)3-4 5.2 2.4
7.5 4.0 1.7 (13,21) (
6,10) (19,05) (10,16) (4
,32)5-6 5.2 4.1 7.5 4
．． 0(13,21) (10,41) (19,05
) (10, 16) *The units of numerical values displayed here are inches (Cl11 is in parentheses).

In the present invention, a mandrel is sprayed or coated with a liquid release agent and the mandrel is heated to or held at a temperature of 110'F (43.3C). Base 33 of material 30
is aligned with the longitudinal axis of the mandrel 2o and wrapped over the mandrel, pressing it snugly against the surface of the mandrel and once around the mandrel, pressing it against itself. If the tip insert 40 is to be assembled into the shaft adjacent the end of the club head, the tip insert material 40 is first removed from its release paper and the tip insert material 40 is assembled adjacent the end 32 of the base material 30. It is joined to the base material 30 by gluing.

When the base blank 30 (along with the tip insert 40, if used) is properly seated against the steel mandrel 20, the central blank 50 is added to the assembly. The release paper is removed from blank 50 and base 53 of blank 50 is aligned with the solid axis of steel mandrel 20, preferably at the circumferential point where the final layer of blank 30 generally ends. The material 50 is then pressed to adhere to the material 30 (and the tip insert material 40, if used) and the mandrel 2
0 to engage with the material 30. The tip insert thus creates a plurality of layers of fibers spiraling around the longitudinal axis of the shaft, the fibers being at approximately +45° to the plane containing the longitudinal axis of the shaft.
and at an angle of −45°.

The base 63 of the outer material 60 is then preferably attached to the material 50.
Outer blank 60 is applied to the golf shaft assembly by aligning the longitudinal axis of mandrel 20 at the circumferential point where the final layer of the outer blank 60 generally ends and wrapping blank 60 around blank 50 and mandrel 20.

Edges of inner material, center material and outer material 31°51.6
1 at one end of the shaft and the other end 32, 52.
62 (and end 42 if using a tip insert) at the other end of the shaft.

After all of the material is in place on the mandrel, approximately % inches (1,27 cm) to approximately 374 inches (1,91 cm)
Pressure is applied to the wrap and mandrel by tightly helically wrapping a preferably polypropylene or TEDLAR tape having a width of Ill) around the entire shaft.

(T F, D L A R are E.I. DuPont.
It is a trademark of De Nimoas & Co. ) The taped shaft and mandrel are then placed in an oven to cure the resin. In a preferred embodiment, the resin is an epoxy and the shaft assembly is heated to about 300 degrees Fahrenheit.
(148.89° C.) for approximately 1 hour to harden the epoxy resin and bond the glass fibers of the shaft into a monolithic structure. After about an hour, remove the shaft and mandrel from the oven and heat to about 250°F.
Cool to 11'C). Remove the tape wrap from the shaft and remove the golf shaft from the mandrel. The hardened shaft is then painted with clear epoxy for decoration. The grip end 11 of the shaft is not covered with clear epoxy and may be ground after painting to remove the clear epoxy. It is also a good idea to trim the shaft a fraction of an inch from the end before or after painting it with clear epoxy.

The above procedure is for deflection 1-2 and deflection 3 as pointed out above.
Three basic types of deflections are used in manufacturing the golf club shafts of the present invention, shown as -4 and deflections 5-6. Wood clubs with deflections 1-2 and 3-4 (i.e. driver, 3-wood, 5-wood, etc.)
When manufacturing a shaft for use, the tip 3 of the base material 30 is
The base material 30 is cut so that the width of the grip end 31 is approximately 2.4 inches (6.10 cm) and the width of the grip end 31 is approximately 5.2 inches (13.21 cm). For a shaft with a deflection of 1-2, the outer material 60 has a deflection of about 2.0 mm at the tip 62.
9 inches (7,37cn) wide, approx. 5 at grip end 61
, with a width of 14.48 cm. Deflection 1-
The shaft tip insert 40 with 2 is approximately 2.5 inches (6.35 cm) wide.

In manufacturing golf shafts for woods having a deflection of 3-4, the inner stock 30 is approximately 2.4 inches wide at the tip 32.
10 cm), approximately 5.2 inches wide at the grip end (13,
21 cll). The outer material 60 has a diameter of about 4 mm at the tip 62.
It has a width of 0 inches (10,16 cs+) and a width of approximately 7.5 inches (19,05 (!11) at the grip end 61).

The tip insert 40 is about 1. It has a width of two feet (4.32 cm).

When manufacturing a golf club shaft having a deflection of 5-6, the inner stock 30 has a diameter of approximately 4.1 inches at its distal end 32.
It has a width of 10,41C11) and a width of 5.2 inches (13,23(2)) at its grip end. Outer material 60 is approximately 4.0 inches (10,161) wide at its distal end 62;
It has a width of approximately 7.5 inches (19.05 cs+) at its tip 61. In the manufacture of a shaft with a deflection of 5-6,
Tip inserts 40 are generally not included, although these may be used if desired for heavier shafts.

The central blank 50 used in the manufacture of shafts having deflections of 1-2, 3-4 and 5-6 has a width of 3.9 inches (9,91(2)) at the gripping end 51 as noted above; It has a width of 1.9 inches (4.83 cll) at the tip 52.

As pointed out above, the inner material 30 and the tip insert 40
And the preferred material for the outer material 60 is a 45571@molded glass fiber fabric made of S-2 glass fiber impregnated with epoxy resin. For example, the specifications for epoxy-impregnated fiberglass cloth, such as that manufactured by Clark-Schwebel, are as follows.

Thread count (number of threads per inch)
57X30 Warp 5CG150 'A Weft 5CG150 % Unit area 1 axis weight 5.4 oz/yd" (33,
9g/rrr) Thickness 0.
0055 in (0,01397 cm+) Breaking Strength 350X60 inner stock 30 and outer stock 60 are cut during manufacture with warp threads oriented so that they run parallel to the longitudinal axis of the shaft.

The tip insert 40 is cut so that the glass fibers extend at 45 degrees to the longitudinal axis of the shaft.

For a shaft having a deflection of 1-2, the inner stock 30 makes up about 34% of the glass fibers in the shaft, the central stock 50 makes up about 28% of the glass fibers, and the outer stock 60 makes up about 38%. do. For a shaft having a deflection of 3-4, the inner stock 30 comprises approximately 31% of the glass fibers in the shaft, the central stock 50 comprises approximately 25% of the glass fibers, and the outer stock 60 comprises approximately 44% of the glass fibers.
make up %. For a shaft with a deflection of 5-6, the inner blank 3o constitutes 36% of the glass fibers in the shaft, the central blank 5o constitutes approximately 23% of the glass fibers, and the outer blank 6o constitutes approximately 40% of the glass fibers. Configure. If a tip insert material is used, the tip insert material comprises 7% to 9% of the total glass fibers in the shaft.

The three types of shafts of the present invention exhibit a reasonable variety of deflections to meet the needs of both experienced and novice golfers. Substantial changes in the deflection of golf clubs made with the golf shafts of the present invention can be further achieved by trimming the length of the club. For example, in order to manufacture a driver, the most flexible basic shaft, i.e. deflection 1
-2, if you assemble the golf shaft by trimming 2 inches (5,08csa) from the grip end of the shaft, you will get a deflection of 1;
The next level of stiffness, Deflection 2, is achieved by trimming 2 inches from the tip of the -2 shaft. The deflection can be varied between Deflection 1 and Deflection 2 by selectively trimming from both the grip end and the tip of the shaft prior to assembly of the shaft into the driver.

The above procedure allows golf club shafts to be produced with stiffness increasing in generally uniform steps from Deflection 1 to Deflection 6.

Unlike most golf club deflection measurements, which are done by clamping the grip end and placing a weight on the tip of the shaft, the golf shaft of the present invention is better suited to the player and provides a more consistent hit. In order to produce a golf club that is easy to use, the deflection of this golf shaft is measured at both ends of the shaft. Thus, golf shafts of the present invention are measured for deflection by clamping each end and attaching weights to the unclamped ends to measure deflection. The typical deflection of the driver shaft of the present invention when the grip end is clamped and a 5 lb (2,268 kg) weight is placed on the shaft 35 inches (88,9 cm) from the grip end is as follows: 42.7 from the edge
Measures from about 4 to about 6 inches (10.16 to 15.24 cm) at 5 inches (108.59 cm). On the other hand, the tip of the same shaft is clamped, and a 5 bond (2,2681 tr) weight is attached 3 times from the tip.
When hung on the shaft at 5 inches (88,9 cm), it is 42.75 inches (108,59 cm) from the tip.
Approximately 9 to 1 inch (22,86 to 43.1
The deflection of 8 layers m) is measured.

The shaft of flexure 1-2 of the invention weighs approximately 80±4g; the shaft of flexure 3-4 of the invention weighs approximately 89±4g
The weight of the shaft of the present invention is 92±
It weighs 4g. Typically, wood shafts are approximately 45 ± 18 inches (114,3 ± 0.318 cm) in finished form.
) is trimmed to length.

The first cross section of the wall IOC of the golf club lO for irons.
Shown in Figure B. Preferably, the wall 10c of the golf shaft 10 has approximately eight layers of fibers. Each layer of fiber provides a thickness of about 0.006 inches (0.0152 cm) to the wall of the shaft, and the total wall thickness of the preferred glass shaft is about 0.048 inches (0.1219011). As shown in Figure 1B, the golf shaft consists of three separate [H5c, 16C1 and 17C]. inner group 1
5c is formed of two or three glass fiber layers, and these glass fiber layers are aligned with the solid axis 1 of the shaft lO.
0b and a plurality of glass fibers 15e extending about the solid axis 10b of the shaft 10 at substantially right angles to the solid axis 10b of the shaft. There is. The central group 16C has approximately 4 layers, and the axis 10b of the shaft 10
It consists of a number of graphite fibers extending at selectively varying angles around the . The four layers of graphite fibers are at approximately 20° to 45° to the plane passing through axis 10b.
two layers of fiber 16d spiraled about axis 10b at a selected angle of about 340° to 315° (i.e. about -20° to -
It has two layers of fibers 16e spiraled around axis 10b at an angle of 45°). The outer group 17c has about 2 fibers 17d extending approximately parallel to the longitudinal axis 1ob of the shaft 10 and approximately 2 fibers 17e extending approximately perpendicular to the longitudinal solid axis of the shaft 1o. Consisting of layers of glass fiber.

The thicker end 11 of the shaft lO is adapted to receive a grip, as is known in the art, which grip often fits the player's hand and allows the player to comfortably grip the shaft. It is a molded rubber member that is fitted into the end portion 11. The other narrow end 12 has a uniform diameter extending 4 inches (10,16 cm) from the end;
And it can be fitted into the hosel of an iron golf club head.

A shaft for an iron golf club is also shown in FIG. 2 and manufactured with the steel mandrel 20 described in Retirement.

ζ 1 FIG. 7 is a plan view of the base material, ie, the inner material 70 of resin-impregnated glass fiber cloth cut to form the inner layer 15C of the golf club shaft 10 for irons. As shown in FIG. 7, the blank 70 is rectangular with a straight base 73 and an opposite side 74 approximately 41 inches (104,14 cm) long. End 71.
72 is generally located at right angles to base 73 and is approximately 3.3
It has a width of 0 inches (8.38 cm). As shown in FIG. 7, blank 70 is cut from a resin-impregnated glass fiber cloth having glass fibers extending at right angles to each other.

Certain preferred glass fiber cloths include, for example, Clark
It is made of S-2 glass, type 4557, such as manufactured by Schwepel, and the majority of the glass fibers in this glass fiber cloth (warp 1 inch (2,54 cm)
Cut the glass fiber cloth so that the 57 pieces per ) extend parallel to the base 73 of the material as indicated at 15d in FIG.

A small portion of the fabric glass fibers 15e (30 per inch of weft) extend approximately perpendicular to the base 73 of the material and the fibers 15d. Although it is not intended to limit the ratio of the number of glass fibers extending parallel to the base 73 to the number of glass fibers extending in the lateral direction of the base 73, 1
Preferably, there are approximately twice as many glass fibers extending parallel to base 73, indicated at 5d, as there are glass fibers extending perpendicular to base 73, indicated at 15e.

Figures 8 and 9 show the central layer 1 of an iron club shaft.
FIG. 6 is a plan view of materials 80 and 90 for 6c. These materials 80 and 90 are approximately 41 inches long (104, 14c
m) bases 83.93 and ends 81.82.91.92 extending at right angles from these bases 83.93.

The first sides 81 and 91 of these materials 80.90 are approximately 3
．． The second side 82 has a width of finch (9,40 cm).
and 92 is approximately 1. It has a width of finch (4,32 values). The fourth sides 84 and 94 of the central blank extend in a straight line between the first sides 81 and 91 and the second sides 82 and 92. Materials 80 and 90 preferably weigh 150 g
/rrl air-containing fiber density (Fiber ari
It is cut from a unidirectional graphite fiber epoxy resin tape with a high density. Such a unidirectional graphite fiber epoxy resin tape is manufactured by Ferro Corporation (F
Manufactured by Erro Corp, ), floor cE32
It is sold under the name 1R. Materials 80 and 90 are the 8th
As shown in the Figures and FIG. 9, the graphite fibers are cut so that they are selectively oriented at varying angles with respect to their bases 83 and 93. Thus, materials 80 and 90 have fibers 16d and 16e at bases 83 and 93.
The pieces are cut to make angles A and -A, respectively. The selected angles A and -A are about +20° to about +45° and about -20° to about - with respect to bases 83 and 93, respectively.
45°. The angular orientation of the graphite fibers relative to the bases 83 and 93 is selected to control resistance to longitudinal and torsional deflection of the shaft. Angularly oriented fibers, when assembled into a shaft, do not substantially increase the longitudinal stiffness of the shaft, but increase its torsional stiffness, reduce its torsional deflection, and Significantly reduces the tendency for shaft breakage due to separation of glass fibers at the ends.

At positive and negative angles of about 45° (A and -A), the shaft flexes and twists more along its longitudinal axis than at positive and negative angles of about 20° (A and -A). Low resistance to deflection. That is, the angles A and −
As A decreases from about 45° to about 20°, shaft deflection decreases and resistance to torsional deflection increases.

FIG. 1O shows blank 100 for the outer layer 17C of fibers that make up the iron shaft IO.

This material 100 is approximately 41 inches long (104,14C1
1) has a straight base 103 and an opposite side 104. Ends 101, 102 are located substantially perpendicular to base 103 and are approximately 4.2 inches (10,16 cm.
) width. The outer material 100 is cut from the same glass cloth as the inner material 70. Similar to the inner material 70, the outer material 100 has the majority of the glass fibers of the glass fabric 17
The fibers 17e are oriented parallel to the base 103 as indicated at d and are cut so that the transverse fibers 17e lie substantially perpendicular to the base 103.

In the present invention, positive and negative angles (A and -A) are selected to form three different iron shafts with equal inner diameters but with three different bending properties of the longitudinal axis and three different torsional resistances. In this way, the iron shaft 10 is manufactured.

For example FS-100, FS-200, and FS-300
These three grades of iron shafts have uniformly spaced deflections over the most desirable range of iron shaft deflections. The table below shows the selection of angular orientations of the graphite fibers in the central layer for producing three iron shafts of the invention.

The top of the soil is outstanding again” Seibu V λLFS-10
0 (flex) 45°FS-2
00 (medium) 30°FS-300 (stiff) 20
In the present invention, iron shafts are manufactured using substantially the same procedure as wood shirts. Spray or coat the mandrel with a liquid stripper and heat the mandrel to 110°F.
3°C) or maintained at this temperature. Material 70
align the base 73 of the mandrel with the longitudinal axis of the mandrel 20 forming the 8 inch (20,32 cm) long handle portion 11, and press the base 73 snugly against the surface of the mandrel and rotate the mandrel more than once. Then wrap it around the mandrel, pressing it tightly against itself.

When the base blank 70 is properly attached to the steel mandrel 20, the central blanks 80 and 90 are added one after another to the assembly. The release paper is removed from blanks 80 and 90, and the bases 83 and 93 of blanks 80 and 90 are aligned with the solid axis of steel mandrel 20, preferably at the circumferential point where the final layer of blank 70 generally terminates. Next, material 8
0 to adhere to the material 70 and tightly wrap it around the mandrel 20 to engage the material 70. Material 90 is then pressed to adhere to material 80 and tightly wrapped around material 80 to form an assembly.

Base 103 of outer blank 100 is then aligned with the longitudinal axis of mandrel 20, preferably at the circumferential point where the final layer of blank 90 generally ends, and blank 60 is wound around blank 90 and mandrel 20. Attach the outer blank 60 to the golf shaft assembly. Thus, the central layer of the shaft includes fibers spiraled about the longitudinal axis of the shaft at an angle within the range of about ±20° to about ±45° with respect to a plane containing the longitudinal axis of the shaft. has.

Edges of inner material, central material and outer material 71.81.9
1 and 101 at one end of the shaft, and the other end 72
．． 82, 92, and 102 at the other end of the shaft. After all of the material is in place on the mandrel, approximately A
inch (1,27 cm) to approximately 41 inches (1,91 cm)
Pressure is applied to the wrap and the 7-ndrel by wrapping a preferably polypropylene or TEDLAR tape, having a width of 1 cm), tightly helically around the entire shaft. (TEDI, AR are trademarks of EI du Pont de Nimois & Co.) The tape-wrapped shaft and mandrel are then placed in an oven to cure the resin. In a preferred embodiment, the resin is an epoxy and the shaft assembly is heated to approximately 300°F (148.8°F).
9° C.) for approximately one hour to harden the epoxy resin and bond the glass fibers of the shaft into a unitary structure.

After about one hour, remove the shaft and mandrel from the oven and cool to about 250"F (121,11C). Remove the tape wrap from the shaft and remove the golf shaft from the mandrel.

The hardened shaft is then painted with clear epoxy for decoration. The grip end 11 of the shaft is not covered with clear epoxy and may be ground after painting to remove the clear epoxy. It is also a good idea to trim the shaft a fraction of an inch from the end before or after painting it with clear epoxy.

In an iron shaft, the inner stock 70 makes up about 25% of the fibers of the shaft, the center stock 8° and 90 makes up about 43% of the fibers, and the outer stock 100 makes up about 32%.

The three iron shafts of the present invention provide a reasonable variety of deflections to meet the needs of both experienced and novice golfers.

The present invention provides a golf club that is lightweight, has a more predictable degree of deflection, matches the characteristics of the golf club to the abilities of various players, and can create a golf club that extends distance over conventional golf clubs. Provide shaft.

Also, unlike prior art fiberglass clubs, the shafts of the present invention are not susceptible to breakage or excessive torsional deflection, and can be cut to vary deflection in a predictable manner; Furthermore, heads having standard dimensions in the golf industry can be installed.

Although preferred embodiments of the invention have been disclosed, other embodiments will be apparent to those skilled in the art. This description of the preferred embodiments is not intended to be limiting; the invention is limited only by the scope of the claims.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of a shaft of the present invention; FIGS. 1A and 1B are enlarged cross-sectional views of a wall of a golf club shaft showing a glass fiber layer; FIGS. 2-10 are a partial cross-sectional view of a shaft of the present invention; 2 shows a steel mandrel and a glass fiber material used in the manufacturing method; FIG. 2 shows a steel mandrel for manufacturing the golf shaft of the present invention; FIG. 3 shows a glass fiber material with an inner glass fiber layer phase. Figure 4 is a view of the glass fiber stock for the shaft tip insert; Figure 5 is a view of the glass fiber stock for the central glass fiber hire; Figure 6 is a view of the glass fiber stock for the outer glass fiber hire; Figure 7 is a diagram of the fiber material of the inner layer of fiber for the shaft of an iron club;
Figure 8 is an illustration of the fiber material of the central layer of fiber for the shaft of an iron club; Figure 9 is an illustration of the fiber material of the central layer of fiber for the shaft of an iron club;
The figure is a diagram of the fiber material of the outer layer of fiber for an iron club shaft. 10...Golf shaft, 11...One end portion, 12...Second end portion, 13...
・Central part, wall of shaft for 10a, 15-1
7...layer, 15a, 15b, old...glass fiber, 20...steel mandrel, 3o...
...Inner material, 40...Tip material, 50.
...Central material, 60...Outer material.

Claims (1)

[Scope of Claims] 1. Consisting of a generally tapered hollow shaft having a wall portion composed of a plurality of fiber layers and a cured resin that bonds the plurality of fiber layers to each other to form an integral structure; A shaft having a length of several inches of constant diameter adjacent to one end, a length of several inches of constant diameter of a smaller diameter adjacent to the other end, and a uniformly tapered portion intermediate these end portions. one end has a diameter adapted to support a golf grip on its outer surface, and the other end has a diameter adapted to fit into a hosel of a club head; A golf club shaft characterized in that the constant diameter portion allows for the production of golf clubs with variable bending properties by cutting the shaft to a length appropriate for the golf club. 2. Claim 1, characterized in that the wall of the shaft consists of an inner group of layers, a middle group of layers and an outer group of layers.
The golf club shaft described in section. 3. The golf club shaft of claim 2, wherein the central group of layers has one or more layers of fibers spiraled at a selected angle about the longitudinal axis of the shaft. . 4. The selected angle is about 20° to about 45° and about -20°
The golf club shaft according to claim 3, characterized in that the angle is between -45[deg.] and -45[deg.]. 5. Claims characterized in that the end of the shaft adapted to be fitted into the hosel of the club head further has another group of layers intermediate the base group of layers and the central group of layers. The golf club shaft according to item 1. 6. The golf club shaft of claim 5, wherein the fibers of the other groups of layers are positioned at selected angles of about ±45° relative to the longitudinal axis of the shaft. 7. The shaft has walls consisting of 6 to 8 layers of glass fibers, the inner group of layers being 2 to 3 layers with the glass fibers arranged generally parallel and at right angles to the longitudinal axis of the shaft. The middle group of layers consists of about two layers with their glass fibers arranged generally parallel to the longitudinal axis of the shaft, and the outer group of layers consists of about two layers with their glass fibers arranged generally parallel to the longitudinal axis of the shaft. The golf club shaft according to claim 1, characterized in that it comprises two to four layers arranged in parallel and at right angles. 8. The shaft has a length of approximately 114.3 cm, with one end having a diameter of approximately 1.575 cm and a length of approximately 30.48 cm, and the other end having an outer diameter of approximately 0.851 cm and a length of approximately 0.584 cm.
2. The golf club shaft of claim 1, having an inner diameter of approximately 15.2 mm and a length of approximately 15.2 mm. 9. The curing resin is epoxy, and the glass fibers are pre-impregnated with epoxy, the glass fibers are arranged in layers along their entire length, and the outer and inner groups of layers are located parallel and at right angles to the axis of the shaft. The center layer is formed from woven resin-impregnated glass fibers with the glass fibers oriented so that the central layer is formed of glass fibers located substantially along the axis of the shaft, and the central layer is formed from glass fibers located substantially along the axis of the shaft at the end of the shaft to be fitted into the club head. an adjacent fourth layer group has resin-impregnated woven glass fibers oriented at a supplementary angle of about 45 degrees to the axis of the shaft, the cured resin bonding the glass fibers of the four layer groups; and integrated into a shaft with selectable deflection and minimal torsional deflection.
The golf club shaft described in section. 10. The golf club shaft according to claim 1, wherein the weight of the shaft is about 80 g to about 95 g. 11, the inner group of layers is about 3 of the glass fibers in the shaft
0-36%, the middle group of layers contains about 23-28% of the glass fibers in the shaft, and the outer group of layers contains about 38-44% of the glass fibers in the shaft. A golf club shaft according to claim 2. 12. The shaft has a further woven fabric positioned at a supplementary angle of 45 degrees to the axis of the shaft for a distance of approximately 50.8 cm at the end of the shaft adapted to be fitted into the hosel of the club head. 12. The golf club shaft according to claim 11, comprising glass fiber. 13. Claim 12, wherein the further glass fibers at the end of the shaft adapted to be fitted into the club head are about 7-9% of the glass fibers in the shaft. Golf club shaft as described. 14. The shaft has an inner group of about 2 layers with glass fibers arranged generally parallel and perpendicular to the longitudinal axis of the shaft and about 20 layers of graphite fibers arranged about the longitudinal axis of the shaft. a central group of about four layers arranged in a helical manner at selected angles of 0° to about 45° and about -20° to about -45°, with the glass fibers being arranged relative to the longitudinal axis of the shaft; 2. A golf club shaft as claimed in claim 1 having in its walls approximately eight fiber layers comprising an outer group of approximately two layers arranged generally parallel and perpendicular. 15. The shaft has a length of about 104.14 cm, with one end having a diameter of about 1.575 cm and a length of about 20.32 cm, and the other end having an outer diameter of about 0.94 cm and a length of about 0.5 cm.
15. The golf club shaft of claim 14 having an inner diameter of 84 cm and a length of 10.16 cm. 16. The golf club shaft of claim 15, wherein the weight of the shaft is about 72 g to about 85 g. 17. Cut the epoxy-impregnated glass fiber cloth into a base material having a long base and glass fibers oriented parallel and at right angles to the base; cut the epoxy-impregnated parallel glass fiber rows into long Create a central material with a base, a wide grip end, and a narrow tip; cut the epoxy-impregnated glass fiber cloth to create an outer material with a long base and glass fibers extending parallel and at right angles to the base; peel. Prepare a coated mandrel and keep the mandrel at a temperature that aids in assembling the materials but below the curing temperature of the resin; align the base of the inner base material with the longitudinal axis of the mandrel and place multiple base materials together. Wrap the center material around the mandrel in layers; align the base of the center material with the longitudinal axis of the mandrel; wrap the center material around the base material in multiple layers; Wrap the outer material in multiple layers around the central material, aligned with the longitudinal axis; press the assembled material against the mandrel by spirally wrapping the removable tape across the shaft; A method of manufacturing a golf shaft, comprising placing the rolled shaft and mandrel in an oven to cure the resin and form an integral structure. 18. The base material and the outer material are epoxy-impregnated fiberglass cloth with a wide gripping end and a narrow tip, and the central material is an epoxy-impregnated parallel fiberglass cloth extending generally parallel to the base of the material. 18. A method according to claim 17, characterized in that it is a glass fiber array. 19. Attach the tip insert material to the mandrel between the inner material and the center material, the insert material being cut from epoxy-impregnated glass fiber cloth, and attaching the insert material so that the glass fibers are on the mandrel. 4 to the axis
19. A method as claimed in claim 18, characterized in that it is attached to the mandrel so as to extend at a supplementary angle of 5 degrees. 20. A golf shaft with increased ease of hitting and feel manufactured by the method according to claim 18. 21. A golf shaft with increased ease of hitting and feel manufactured by the method set forth in claim 19. 22. The inner material is about 30~ of the glass fiber of the shaft.
36% of the glass fibers of the shaft, the central material having about 23-28% of the glass fibers of the shaft, and the outer material having about 39-44% of the glass fibers of the shaft. A golf shaft with increased ease of hitting and feel manufactured by the method described in . 23. The tip insert is approximately 9% of the glass fiber of the shaft.
The inner material is approximately 31 mm of glass fiber in the shaft.
%, and the central material has approximately 2% of the glass fiber of the shaft.
20. A golf shaft with increased strikeability and feel made by the method of claim 19, wherein the outer material has about 35% of the glass fibers of the shaft. . 24. The tip insert is about 7% of the glass fiber of the shaft.
The inner material is approximately 29 mm of glass fiber on the shaft.
%, and the central material has approximately 2% of the glass fiber of the shaft.
20. The improved hitability and feel golf club shaft of claim 19, wherein the outer material comprises approximately 41% of the glass fibers of the shaft. 25. The inner material is approximately 36% of the glass fiber of the shaft.
The central material has approximately 23 mm of glass fiber in the shaft.
% and the outer material comprises about 40% of the glass fibers of the shaft. . 26. The tip insert material is glass fiber 7 of the shaft.
Claim 19 characterized in that it has a
A golf club shaft with increased ease of hitting and feel manufactured by the method described in Section 1. 27. said base material and said outer material are epoxy-impregnated glass fiber cloth, the central material is parallel rows of epoxy-impregnated graphite fibers extending at a positive selected angle relative to the base of the material, and the additional central material is This additional central material is cut from parallel rows of epoxy-impregnated parallel graphite fibers with a long base, a wide grip end, and a narrow tip, with the graphite fibers extending at a positive selected angle to the base. is aligned with the longitudinal axis of the mandrel and is wound onto the mandrel before adding the outer material.
The method described in Section 7. 28. The positive selected angle of the fibers of one central stock is from about 20° to about 45° and the negative selected angle of the fibers of the other central stock is from about -20° to about -45°. 28. A method according to claim 27, characterized in that: 29. A golf shaft with increased ease of hitting and feel manufactured by the method set forth in claim 27. 30. Claim 28, wherein the inner material has about 25% of the fibers of the shaft, the central material has about 43% of the fibers of the shaft, and the outer material has about 32% of the fibers of the shaft. A golf shaft with increased ease of hitting and feel manufactured by the method described in . 31. Claim 30, characterized in that the selected angles of the fibers of the central layer are +20° and -20°.
The golf club shaft described in Section 1. 32. Claim 30, characterized in that the selected angles of the fibers of the central layer are +30° and -30°
The golf club shaft described in Section 1. 33. Claim 30, characterized in that the selected angles of the fibers of the central layer are +45° and -45°
The golf club shaft described in Section 1. 34, a wall thickness of approximately 0.0 mm made of multiple glass fiber layers.
Equipped with a 122cm overall tapered hollow cylindrical wall,
The glass fiber layer is impregnated with an epoxy resin that is cured to bond the glass fiber layers together into a unitary structure; the glass fiber layer has a length of about 4 inches and a diameter adjacent to one end. The length of the constant part is 30.48
cm, and the length of the constant diameter part adjacent to the other end is 20.
32 cm, said one end having an outer diameter of about 1.575 cm and adapted to receive a golf grip on its outer surface, and said other end having an outer diameter of about 0.851 cm and an inner diameter of about 0.584 cm. What is claimed is: 1. A golf club shaft comprising: a golf club shaft which is fitted into a hosel of a club head; 35. A golf club shaft comprising a plurality of fiber layers, wherein the fiber layer is impregnated with an epoxy resin that cures to bond the plurality of fiber layers together into a unitary structure, and wherein one of the plurality of layers The inner layer of the fiber layer is helical about the longitudinal axis of the shaft at a selected positive angle to this axis and the inner layer of fiber is helical about the longitudinal axis of the shaft at a selected negative angle to this axis. the shaft has a length of approximately 104.14 cm of constant diameter adjacent one end and a length of approximately 10.16 cm of constant diameter adjacent the other end.
m in length, said one end having an outer diameter of about 1.575 cm and adapted to receive a golf grip on its outer surface, and said other end having an outer diameter of about 0.940 cm and an outer diameter of about 0.0 m.
．． A golf club shaft comprising a generally tapered hollow cylindrical wall approximately 0.122 cm thick having an inner diameter of 584 cm and adapted to fit into the hosel of a club head.